mine was done all in my smallish 2 car garage. no power tools, no welder, no lift. did it over the winter of 2005-06, when the z is normally off the road anyway. i did have; an LS1 expert that did an initial tune to my pcm then later tuned it on his new dyno [i also sourced many parts from him and bugged for much advice], wiring guy-he did the work to adapt the pro-comp gauges and tied the datsun to gm harnesses together, welder guy-basically built the exaust system [had the z flatbedded there after it was 'fired up']. all in all, very satisfying to know that i [pretty much] built it myself!
remember, it always takes longer than it does...